Thermoelectric systems are used in a variety of fields and devices, and operate by the Peltier effect, which creates a heat flux between the junction of two different types of materials. Thermoelectric systems that incorporate a Peltier device can be used for heating or cooling, and can further be used as temperature controllers in a wide range of applications. Unlike other known cooling technologies, such as vapor-compression refrigeration, a thermoelectric cooling element acts as a solid-state active heat pump that does not require any moving parts or circulating liquid. In addition, the small form factor and low maintenance of thermoelectric cooling elements makes them desirable for incorporation into smaller systems and devices, such as consumer products. Thermoelectric cooling elements also have a long life, and can be easily controlled by changing the input voltage/current. However, thermoelectric cooling systems are not widely used for refrigeration because of lower efficiency as compared to conventional compression cycle systems.
Thermally insulated carafes, such as pitchers, mugs, cups, and other containers are well known in the industry of consumer products, and are used to keep the contents of the carafe at a constant temperature, generally to preserve warmth or coolness. The thermal insulation of such carafes may be achieved in various ways. For example, some carafes utilize a thicker wall, often made out of a material with low thermal conductivity such as glass, porcelain, earthenware, or ceramics, to minimize heat transfer between the contents and the outside environment. Other carafes include a double-wall exterior, where air is trapped between the inner and outer walls of the carafe and acts as an insulator. Alternatively, the air between the inner and outer walls of the carafe may be evacuated while the walls are joined together to form a near-vacuum within the walls, which prevents heat transfer by conduction or convection. To further preserve the temperature of its contents, many carafes are actively heated or cooled by an associated system. For example, the carafe of coffee makers is often set on a hot plate to continuously warm the contents of the carafe.
The need to maintain the temperature of a carafe's contents is especially important where the carafe is used to hold a consumable liquid, such as a beverage. Many consumers enjoy cold and hot beverages such as coffee, tea, juice, cocktails, and water at a specific temperature range, and often consume such beverages over an extended amount of time. Thermally insulated carafes are often used to keep such beverages warm or cool during the course of consumption, but the effectiveness of known thermally insulated carafes are not always sufficient, especially where the contents of the carafe must be maintained at a substantially constant temperature for more than a few hours.
For example, many coffee and tea drinkers prefer fresh milk or cream in their beverage instead of a powdered creamer, but often go without due to the absence of this perishable beverage. Cafes and coffee shops often provide thermally insulated carafes, such as the double-walled carafes and vacuum carafes discussed above, which can keep dairy products like milk and cream cold for several hours. Keeping dairy products at a sufficiently low temperature is imperative for preventing the growth of potentially harmful bacteria, and to keep the dairy product from spoiling. The staff of cafes and coffees shops must constantly monitor the temperature of these carafes containing dairy products, refill them as they run out, and refrigerate or discard any excess that was not used during business hours. Furthermore, in settings like the home, office, hotel, or other areas with coffee and tea stations, there is often no staff available to manage the station on a full time basis. Many of these coffee and tea stations also do not have a kitchen area or refrigerator in which to keep dairy products. Accordingly, these beverage stations often offer non-dairy creamer that have a long shelf life and require no refrigeration, generally containing powdered hydrogenated vegetable oil, which is an unhealthy and less desirable alternative to fresh dairy products. In such situations, it is desirable to have a small refrigeration device that can maintain consistent cooling of dairy products over a long period of time, such as across day or even weeks.
The above scenario is only one example of why refrigeration may be required on a small scale without the use of large systems like a compression cycle cooling system, which would be unfit for cooling a small device like a carafe. One of ordinary skill in the art would appreciate that small-scale refrigeration may be used in a wide variety of applications across different industries. While there currently exists some thermoelectric cooling devices for purposes of food and beverage refrigeration, these devices have drawbacks in their inefficiency, as well as the need for an appropriate thermal management system, generally a heat sink and fan that results in large and aesthetically unpleasing designs. Therefore, a need exists for a thermoelectric cooling system that has a small form factor, high efficiency, a compact yet efficient thermal management system, is cost effective, and can be incorporated into devices in an aesthetically pleasing manner. Such a thermoelectric cooling system may be used in conjunction with a thermally insulated carafe to provide consistent cooling of the carafe's contents over a long period of time without user intervention. A need further exists for a thermoelectrically cooled carafe that is aesthetically pleasing, compact, and an economic option for the consumer. A need further exists for a beverage carafe lid that minimizes buildup as the beverage is poured, is easy to disassemble and clean, and is aesthetically pleasing.